U.S. patent number 5,143,459 [Application Number 07/633,782] was granted by the patent office on 1992-09-01 for bayonet spindle mount and a method therefore.
This patent grant is currently assigned to Storage Technology Corporation. Invention is credited to Daniel J. Plutt.
United States Patent |
5,143,459 |
Plutt |
September 1, 1992 |
Bayonet spindle mount and a method therefore
Abstract
A housing having a spindle mount for mounting a spindle
supporting magnetic disks for a magnetic data storage disk system.
A bearing cap having seals is mounted on the exterior of the
housing. A spindle clamp having a male bayonet mount is inserted
through the bearing cap and engages a mounting cup having a female
bayonet mount. A belleville washer is mounted onto the clamp
between the bearing cap and the head portion of the clamp. The
clamp and cup are designed so that the washer is compressed as the
bayonet mount engages. This exerts a constant uniform pressure on
the bearing cup as well as restraining the bayonet mounting from
disengaging. The bearing cap is held tightly against the exterior
of the housing as well to seal the bearing and the inner housing
from the exterior environment.
Inventors: |
Plutt; Daniel J. (Boulder,
CO) |
Assignee: |
Storage Technology Corporation
(Louisville, CO)
|
Family
ID: |
24541106 |
Appl.
No.: |
07/633,782 |
Filed: |
December 26, 1990 |
Current U.S.
Class: |
384/537;
G9B/33.035; G9B/25.003; G9B/19.028; 403/26; 360/98.07; 403/261 |
Current CPC
Class: |
F16C
25/08 (20130101); F16C 35/12 (20130101); G11B
19/2009 (20130101); G11B 33/14 (20130101); G11B
25/043 (20130101); Y10T 403/19 (20150115); F16C
2370/12 (20130101); F16B 2200/406 (20180801) |
Current International
Class: |
F16C
35/12 (20060101); F16C 35/00 (20060101); F16C
25/00 (20060101); F16C 25/08 (20060101); G11B
19/20 (20060101); G11B 33/14 (20060101); G11B
25/04 (20060101); F16C 043/00 () |
Field of
Search: |
;384/609,215,217,227,295,428,439,493,537,539,584,585 ;403/26,261
;360/98.07,98.08,99.04,99.08 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Stodola; Daniel P.
Assistant Examiner: Gayoso; Tony A.
Attorney, Agent or Firm: Dorr, Carson, Sloan &
Peterson
Claims
I claim:
1. An apparatus for mounting a spindle for rotation in a housing,
said apparatus comprising:
a spindle;
a housing for containing said spindle
bearing means for rotatably mounting said spindle;
a circular mounting cap having an upper portion for receiving said
bearing means;
means for clamping said mounting cup to a first surface inside said
housing;
said clamping means comprising:
a tubular clamp having a lower end abutting against a second
surface on the outside of said housing to clamp said cup against
said first surface on the inside of said housing;
first teeth formed around the outer circumference of the upper end
of said clamp, said first teeth extending radially outward a
predetermined distance from the longitudinal axis of said clamp and
extending longitudinally inward a predetermined distance from said
upper end of said clamp;
an inner hole formed in the lower end of said cup extending
longitudinally at least partway into said cup;
second teeth formed about the inner circumference in said inner
hole at said lower end of said cup, said second teeth extending
radially inward a predetermined distance from said inner hole and
extending longitudinally inward a predetermined distance from said
lower end;
wherein said first teeth are inserted in the spaced formed between
said second teeth and said second teeth are inserted in the spaces
between said first teeth so that said upper end of said clamp can
be inserted into said inner hole of said cup;
said predetermined distances being such that after said upper end
of said clamp has been fully inserted into said cup, said cup and
said clamp are rotatable relative to one another to lock said cup
and said clamp from disengagement from each other and to clamp said
cup against said first surface on the inside of said housing;
spring means to resiliently bias said first teeth of said clamp
against said second teeth of said cup to restrain said clamp and
said cup from disengaging from each other and to axially preload
said spindle to isolate said spindle and said bearing from
vibrations and shock; and
bearing cap means mounted between said spring means and said
housing for sealing the interior of said housing from the exterior
environment by the spring means biasing said bearing cap means
against the exterior of the housing.
2. The apparatus of claim 1 wherein said spring means comprises at
least one belleville washer mounted between said clamp and said
cup, said washer being compressible to form said resilient biasing
means as said clamp and said cup are in locked engagement with each
other.
3. An apparatus for mounting a spindle for rotation in a housing,
said apparatus comprising:
a spindle;
a hollow housing having an upper inner surface and a lower inner
surface;
a lower bearing rotatably mounted on said spindle;
a mounting cup having a receiving portion for mounting said lower
bearing;
means for securing said mounting cup against said lower inner
surface of said housing;
an opening extending through said lower surface of said housing
co-axial with longitudinal axis of said spindle;
said securing means including clamping means for rotatably engaging
said mounting cup, said clamping means having a first portion with
a diameter greater than the diameter of said opening and a second
portion with a diameter less than the diameter of said opening for
rotatably engaging said mounting cup through said opening to clamp
said mounting cup against said lower inner surface as said first
portion abuts the outer surface of said housing and said second
portion abuts against a surface of said housing cup;
wherein said clamping means includes:
first teeth formed around the outer circumference of said second
portion, said first teeth extending radially outward a
predetermined distance from the longitudinal axis of said clamping
means and extending longitudinally inward a predetermined distance
from said second portion;
an inner hole formed in the lower end of said cup extending
longitudinally at least partway into said cup;
second teeth formed about the inner circumference in said inner
hole at said lower end of said cup, said second teeth extending
radially inward a predetermined distance from said inner hole and
extending longitudinally inward a predetermined distance from said
lower end;
said first teeth being inserted in the spaces formed between said
second teeth and said second teeth being inserted in the spaces
between said first teeth so that said second portion can be
inserted into said inner hole of said cup;
spring means to resiliently bias said teeth of said clamping means
against said teeth of said cup to restrain said clamping means and
said cup from disengaging from each other;
said predetermined distances being such that after said second
portion has been fully inserted into said cup, said cup and said
clamping means are rotatable relative to one another to lock said
cup and said clamping means from disengagement from each other so
that said first portion of said clamping means abuts against the
outside of said lower housing surface and said receiving portion of
said cup is clamped against said lower inner surface of said
housing, and
bearing cap means mounted between said spring means and said
housing for sealing the interior of said housing from the exterior
environment by the spring means biasing said bearing cap means
against the exterior of the housing.
4. The apparatus of claim 3 wherein said spring means comprises at
least one belleville washer mounted between said clamping means and
said cup, and said washer being compressible to form said resilient
biasing means as said clamping means and said cup are in locked
engagement with each other; and
wherein the interior of the housing is sealed from the exterior
environment by said belleville washer biasing said bearing cap
means against the exterior of the housing.
5. The apparatus of claim 3 wherein said apparatus further
comprises:
an upper bearing rotatably mounted on said spindle;
a second mounting cup having a received portion for mounting said
upper bearing;
second means for securing said second mounting cup against said
upper inner surface of said housing; and
an opening extending through said upper surface of said housing
co-axial with said longitudinal axis of said spindle;
said second securing means including second clamping means for
rotatably engaging said second mounting cup, said second clamping
means having a first portion with a diameter greater than the
diameter of said upper opening and a second portion with a diameter
less than the diameter of said upper opening for rotatably engaging
said second mounting cup through said second opening to form a
locking engagement between said second clamping means and said
second cup so that said lower portion of said second securing means
abuts against the outside of said upper housing surface and said
receiving portion of said second cup is clamped against said upper
inner surface of said housing.
6. An apparatus for mounting a spindle affixed to disks in a
housing for a magnetic data storage system, said apparatus
comprising:
a bearing for rotatably mounting said spindle;
means for securing said bearing to said housing, said securing
means including:
bearing mounting means for mounting said bearing;
bayonet means for engaging said bearing mounting means to secure
said bearing mounting means against a surface of said housing;
an inner hole formed in one end of said bearing mounting means and
extending longitudinally at least part way into said bearing
mounting means;
first teeth portions formed around the inner circumference of said
inner hole at said one end, said first teeth portions extending
radially inward a predetermined distance and extending
longitudinally inward a predetermined distance;
second teeth portions formed spaced about the outer circumference
on one end of said bayonet means extending radially outward a
predetermined distance and extending longitudinally inward a
predetermined distance;
said first teeth portions being inserted in the spaces formed
between said second teeth portions so that said one end of said
bayonet means can be inserted into said inner hole of said bearing
mounting means;
said longitudinally extending predetermined distances being such
that after said bayonet means has been fully inserted into said
bearing mounting means, said securing means are rotatable a limited
distance relative to one another to lock said securing means from
separating from one another;
means for applying a consistently uniform axial preload on said
bearing securing means to securely attach said spindle to said
housing including spring means disposed between said bearing
mounting means and said bayonet means, said spring means
compressible when said securing means are fully inserted and
rotated relative to one another to resiliently bias said first
teeth portions and said second teeth portions against one another
axially to restrain said bearing mounting means and said bearing
means from disengagement so that said first portion of said
clamping means abuts against the outside of said lower housing
surface and said receiving portion of said cup is clamped against
said lower inner surface of said housing; and
means for sealing said bearing from contamination from the exterior
environment.
7. The apparatus of claim 6 wherein said spring means include at
least one belleville washer.
8. The apparatus of claim 6 wherein said sealing means include a
bearing cap mounted on the exterior of said housing between said
housing and said spring means.
9. A method for mounting a rotatable spindle in a housing for a
magnetic data storage disk system using a bayonet spindle mount
having a bayonet mounting cup and a bayonet mounting clamp, said
method comprising the steps of:
(a) mounting a lower spindle bearing in an upper portion of said
bayonet mounting cup;
(b) mounting a bearing cap having a seal on the exterior of the
housing aligned with said rotatable spindle;
(c) inserting over a first end of said bayonet mounting clamp a
compressible spring means for locking together said bayonet
mounting clamp and said bayonet mounting cup;
(d) inserting said first end of said bayonet mounting clamp through
the lower surface of said housing and into said bayonet mounting
cup so that said spring means is between a head portion formed on
the second end of said bayonet mounting clamp and said bearing
cap;
(e) applying a force on said head portion of said bayonet mounting
clamp to compress said spring means prior to said bayonet mounting
clamp being inserted inside said bayonet mounting cup;
(f) inserting said bayonet mounting clamp inside said bayonet
mounting cup;
(g) rotating said bayonet mounting clamp relative to said bayonet
mounting cup so that said bayonet mount is locked to prevent said
bayonet mounting clamp and said bayonet mounting cup from
disengaging; and
(h) removing said force from said bayonet mounting clamp so that
said bayonet mounting clamp and said bayonet mounting cup are
locked together under pressure from said print means which axially
biases said bearing cap to abut against an outer housing surface
while clamping the mounting cup to an inner housing surface.
10. The method of claim 9 wherein step (d) further comprises:
inserting said bayonet mounting clamp through said bearing cap so
that said spring means are between said bearing cap and said head
portion of said bayonet mounting clamp.
11. The method of claim 10 wherein said spring means include a
belleville washer.
12. The method of claim 10 wherein said method further
comprises:
mounting an upper spindle bearing in an upper portion of a second
bayonet mounting cup;
mounting said second bayonet mounting cup to the upper surface of
said housing by a second mounting clamp by repeating the above
steps.
13. The method of claim 9 wherein said spring means include a
belleville washer.
14. An apparatus for mounting a spindle for rotation in a housing,
said apparatus comprising:
a spindle;
a housing for containing said spindle;
bearing means for rotatably mounting said spindle;
a mounting cup having a portion for receiving said bearing means;
and
means for clamping said mounting cup to a first inner housing
surface; said clamping means including:
a clamp for rotatably engaging said mounting cup, said clamp having
a first head means for abutting against an outer housing surface
and a second head means for abutting an opposing surface of said
mounting cup to clamp said mounting cup to said first inner housing
surface as said clamp rotatably engages said mounting cup;
spring means for resiliently biasing said second head means against
said mounting cup surface to restrain said clamp and said cup from
disengaging from each other and to axially preload said spindle to
isolate said spindle and said bearing from vibrations and shock;
and
bearing cap means mounted between said spring means and said
housing for sealing the interior of said housing from the exterior
environment by the spring means biasing said bearing cap means
against the exterior of the housing.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the field of spindle mounting apparatus,
particularly in magnetic data storage disk systems.
2. Statement of the Problem
In magnetic disk drives, the disks are supported on a spindle
within a disk drive housing. These spindles are rotatably driven by
either an internally mounted motor or an externally mounted motor
having a shaft attached to the disk spindle. The disks are driven
at relatively high rates of speed with magnetic read/write heads
moving radially across the disk for reading or recording data at
selective locations on the disks. In disk drives, the relative
positioning between the heads and disk requires great precision.
This precision can be affected by thermal distortion, by vibration,
as well as other factors.
Typically, the spindles are mounted on bearings in the disk drive
housings which are attached by screws to bearing caps. The bearing
caps, in turn, are attached to the drive housing by screws. This
assembly normally requires up to 16 screws to securely attach each
end of the spindle to the drive housing.
The use of screws creates several problems. During installation in
a clean room environment, mounting with screws can result in
particle contamination which can affect the performance of the
assembled disk drive.
Further, the use of screws generate inconsistent loading of the
spindle. The only reliable procedure of testing the loading of the
screws is by gauging the torque on the screws. However, this is
affected by the friction of the screws, misalignment with the pilot
holes, and other factors. The loading of the spindle is critical,
for if the load is too small, the spindle can slip with respect to
the base during usage due to temperature cycling, vibration, or
shock, causing the hard disk assembly to fail. The attachment by
screws also increases the cost of assembly of the disk drive.
Therefore, there exists a need for a spindle clamping arrangement
that will reduce the need for screws, reduce the potential for
particle contamination, and provide a simpler procedure of assembly
that will provide a uniform loading on the spindle.
3. Solution to the Problem
The present invention solves these problems and others by providing
a mount to quickly assemble the spindle in a housing without the
need for a large number of screws.
The present invention further provides a pre-loaded clamping
arrangement applying a consistent and uniform load on the
spindle.
The present invention provides a seal to protect the bearings and
inner housing from contamination.
These and other solutions will become evident from the following
descriptions and drawings.
SUMMARY OF THE INVENTION
The present invention provides a spindle mount for mounting a
spindle supporting magnetic disks in a housing. The spindle is
rotatably mounted in a mounting cup by a roller bearing. The
mounting cup abuts the interior of the housing. The mounting cup
contains a longitudinal hole having radially inwardly extending
teeth to form a female portion of a bayonet mount. A spindle
mounting clamp, which is also hollow, has radially outwardly
extending teeth matching up with the spaces formed between the
teeth of the mounting cup to form the male portion of a bayonet
clamp. The clamp further includes a second end portion forming a
head portion having a larger diameter.
A bearing cap having a seal is mounted on the exterior of the
housing. The clamp is inserted through the bearing cap and engages
the mounting cup through the bayonet mount. A belleville washer is
mounted onto the clamp between the bearing cap and the head portion
of the clamp. The clamp and cup are designed so that the washer is
pre-compressed before bayonet mount engages. This exerts a constant
uniform downward pressure on the spindle restraining the bayonet
mounting from disengaging. The bearing cap is held tightly against
the exterior of the housing as well to seal the bearing and the
inner housing from the exterior environment.
Thus, the spindle is quickly mounted without the need for a large
number of screws. The spindle is axially loaded to withstand
vibrations, shock or thermal distortion. The bearing and disk files
are sealed from the exterior environment to protect against
contamination.
These and other features will become evident from the detailed
description of the preferred embodiment taken in conjunction with
the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view of a prior art spindle mount in a magnetic data
storage disk file system.
FIG. 2 is a cutaway view of the present invention.
FIG. 3 is an exploded view of a perspective of the present
invention.
FIG. 4 is a partial view of the present invention during the
mounting process.
FIG. 5 is a partial view of the mounted invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A prior art magnetic data storage disk file system 10, as
illustrated in FIG. 1, has disks 12 supported on a spindle 14 for
relatively high speed rotation. A motor (not shown) engages the
spindle 14 to rotate the spindle and disks. Magnetic read/write
heads (not shown) move radially across disks 12 to read or record
data on selected tracks on the disks.
In disk drives, the relative positioning between the heads and the
disks requires great precision. This precision can be detrimentally
affected from vibration or shock on the spindle resulting from high
speed start ups and rotation of the spindle and disks, from normal
usage, from thermal distortion within the housing, and from other
factors.
As illustrated in FIG. 1, the prior art devices typically mount
spindle 14 to bearings 16 and 18. Bearings 16, 18 are attached to
bearing caps 20, 22 by screws 24. Bearing caps 20,22 are then
attached to the housing by screws 26. Up to 16 screws for each
bearing are required to mount spindle 14 to the housing.
The use of screws in the prior art devices increases the cost of
assembly and creates particle contamination due to the waste
particles occurring during the screw threading assembly which can
shorten the life span of drive.
The present invention, as illustrated in FIGS. 2-5, overcomes these
problems. The present invention, as shown in one of the preferred
embodiments as shown in FIG. 2, includes a housing 30 having a
plurality of disks 32 supported by spindle 34 for high speed
rotation. Spindle 34 is supported for rotational movement by an
upper bearing 36 and a lower bearing 38. Spindle 34 is engaged by a
drive motor (not shown) at its lower end. The drive motor and means
for attachment to the spindle are well known and do not form a part
of this invention.
The spindle mounting apparatus
As illustrated in FIG. 2, spindle 34 is mounted within housing 30
by bayonet spindle clamp devices 42 and 42'. The spindle clamps 42,
42' are of identical design with spindle clamp 42 clamping the
lower end of spindle 34 at bearing 38 and spindle clamp 42'
clamping the upper end of spindle 34 at bearing 36.
Spindle clamp device 42 is illustrated in FIGS. 2 and 3. The device
42 includes a bearing cup 44, a mounting clamp 72, a bearing cap
60, and a belleville washer 82. As shown in FIG. 2, spindle clamp
42' has corresponding structure including bearing cup 44', mounting
clamp 72', bearing cap 60' and belleville Washer 82'. Only spindle
clamp 42 will be further discussed with spindle clamp 42' having
similar design and operation.
As shown in FIG. 3, lower bearing 38 is adapted to be mounted
within bearing cup 44 to support spindle 34 while allowing free
rotation of the spindle. A lower portion 46 is formed on bearing
cup 44 adapted to abut against the internal surface of housing 30.
This supports spindle 34 as is further discussed below.
An inner hole 48 is formed in cup 44 extending along a vertical
longitudinal axis of the cup 44. An enlarged portion of hole 48 at
the upper end of cup 44 forms a bottom bearing seat 50 for bearing
38. At the lower end 46 of cup 44, radially inward extending teeth
52 are formed as illustrated in FIG. 3. In the embodiment shown in
the FIGS. 2 and 3, there are three teeth 52. The claimed invention
is not meant to be limited to this description. Other variations
forming a bayonet mount, including differing number of teeth and
shapes, are considered to be within the scope of the inventive
concept. Teeth 52 extend longitudinally inward a predetermined
distance. As shown in FIG. 4, inner portion 54 is formed between
the rear of teeth 52 and bearing seat 50. The purpose of inner
portion 54 is to receive the teeth of the mounting clamp as
explained below.
As illustrated in FIG. 4, bearing cap 60 is formed with an inner
hole 62, seal groove 64 and recess 66. The upper portion 70 of
bearing cap 60 has a reduced diameter to closely fit within an
opening formed in the lower housing 30. Bearing cap 60 is designed
to be mounted on the external side of the lower housing 30 to
protect the inner housing from the exterior environment. Bearing
cap 60 is held in place against housing 30 by the spindle mounting
clamp itself, or by the use of mounting screws (not shown).
As illustrated in FIG. 3, the mounting clamp 72 is formed in a
tubular shape having a lower head portion 74 with an enlarged
diameter and an upper toothed portion 76. A belleville washer 82 is
adapted to slide over the upper end 76 of the clamp 72. This
belleville washer 82 is a cone-disk spring capable of producing a
constant load under compression. The purpose of belleville washer
is discussed in further detail below.
The upper portion 76 of clamp 72 includes teeth 78 extending
radially outward as shown in FIG. 3. Teeth 78 are designed to fit
into the spaces between teeth 52 of mounting cup 44. The spaces
between teeth 78 are likewise designed to allow teeth 52 to fit
through the spaces. Teeth 78 extend longitudinally a predetermined
distance to fit into inner portion 54 of cup 44 without interfering
with the bearing 38 as shown in FIG. 4.
The outer diameter of teeth 78 is less than the internal diameter
of hole 62 of bearing cap 60. Clamp 72 is designed for upper
portion 76 to fit through hole 62 of bearing cap 60 as shown in
FIG. 3. Upper portion 76 is adapted to be inserted into hole 48 of
mounting cup 44 with teeth 78 fitting between teeth 52 of mounting
cup 44. Once clamp 72 is fully inserted into mounting cup 44, so
teeth 78 are in inner portion 54, clamp 72 is rotated relative to
cup 44 a limited distance to prevent teeth 78 from disengaging from
cup 44. Other types of bayonet mounts are contemplated as within
the scope of the inventive concept.
Washer 82 is compressed by an external force (not shown) before
clamp 72 is fully inserted into cup 44 as shown in FIG. 4. Once
clamp 72 is full inserted into cup 44 so that teeth 76 are in inner
portion 54, the clamp 72 is rotated relative to cup 44 so that
teeth 76 are no longer aligned with the spaces between teeth 52 of
cup 44. After clamp 72 is rotated, the force against the external
side of clamp 72 is released. The force of the compressed washer 82
biases clamp 72 in the direction away from cup 44, forcing the
lower surface of teeth 78 of the clamp against the upper surface of
the rear of teeth 52 of the cup as illustrated in FIG. 5. The
claimed invention is not meant to be limited in scope to the use of
a belleville washer. Other types of resilient biasing structures
are contemplated as being within the range of the invention as
claimed.
This force from the belleville washer can be chosen by altering the
size of the washer or by stacking washers together. The force from
belleville washer 82 prevents clamp 72 and cup 44 from disengaging
to secure the mounting cup 44 and spindle 34 to the housing 30.
This force provides a consistent, uniform load on the bearing cups
and the base structure to keep the spindle securely attached to the
base during shock, vibration and thermal distortion.
The reaction of the compressed washer 82 acting against bearing cap
60 creates a tight seal between bearing cap 60 and the exterior of
the housing 30 as shown in FIG. 5. A well known type of seal (not
shown) can also be placed in the groove 64 to further seal the
bearing 38 and internal housing from the exterior environment.
Few or no screws are necessary for this mounting. The mounting can
easily occur in a clean room environment without creating
contamination of the system.
A method of mounting the spindle
Spindle 34 has upper bearing 36 and lower bearing 38 mounted onto
it by well known means as shown in FIG. 2. Lower bearing 38 is
mounted in bearing bottom seat 50 of mounting cup 44. Bearing cap
60 is mounted in the opening of housing 30, by screws if desired. A
seal is mounted in groove 64 to lie between cap 60 and external
housing 30.
Belleville washer 82 is mounted over upper portion 76 of clamp 72.
Teeth 78 of clamp 72 are aligned with the spaces between teeth 54
of cup 44. The upper portion 76 of clamp 72 is inserted through
bearing cap 60 and into cup 44.
An external force is applied between clamp 72 and cap 60 until
belleville washer 82 is compressed to allow zero force of insertion
of the clamp assembly into bearing cup 44. Clamp 72 is fully
inserted in cup 44 until teeth 78 are the inner portion 54 of the
cup. Clamp 72 is then rotated relative to cup 44 until teeth 78 are
aligned with teeth 56 of cup 44. The external force is then
removed, with the resultant force being picked up by the housing,
the cup, and the cap. Upper bearing 36 is attached to spindle 34
and housing 30 by similar steps.
The above description of the preferred embodiment is for
descriptive purposes only. The description is not meant to limit
the scope of the concept of the invention as claimed. Other
variations and modifications are considered to be within the scope
of the claimed invention.
The present invention, as set forth in the claims, provides an
apparatus for quickly mounting a spindle in a housing without the
need for additional screws, thus reducing the particle
contamination and inconsistent loading on the disk drive assembly.
This invention provides resists contamination of the system while
providing a consistent and uniform load on the spindle
bearings.
* * * * *